Buoyancy compensator (diving)
A buoyancy compensator also called a buoyancy control device, BC, BCD, stabilizer, stabilisor, stab jacket, wing or ABLJ depending on design, is a piece of diving equipment containing a bladder which is worn by divers to establish neutral buoyancy underwater and positive buoyancy on the surface, when needed. The buoyancy is controlled by adjusting the volume of air in the bladder. The bladder is filled with gas from the diver's air tank or from the diver's mouth.
Features
Regulator first stage
Cylinder valve
Shoulder straps
Buoyancy compensator bladder
Relief and bottom manual dump valve
Regulator second stages (with “octopus”)
Console (pressure gauge, depth gauge & compass)
Dry-suit inflator hose
Backplate
BC inflator hose
Oral inflation mouthpiece and manual dump valve
Crotch strap
Waist strap
All BCs will have some features in common:
A bladder to contain gas which may be added or released during the dive to control buoyancy.
A means of adding gas to the bladder, generally a low pressure direct feed or Power Inflator that injects gas from a low pressure hose from the diving cylinder's diving regulator or an auxiliary cylinder to the bladder(s) of the BC, that is controlled by an inflation valve, and usually an oral inflation option. These are usually at the end of a corrugated rubber inflation hose.